The findings, published in the Journal of the American Medical Association, say that the pharmaceutical industry spent nearly $40 million on marketing opioids to U.S. doctors between 2013 and 2015. Increased opioid marketing by county was associated with a higher overdose mortality rate the following year, the report states.

This is the first study implicating opioid marketing in the opioid crisis, Axios reports, and could be damaging to opioid manufacturers.

The report states the current marketing efforts could counteract national attempts to curb the opioid crisis, and suggests policymakers may want to consider limiting direct-to-physician opioid marketing.

"Policymakers and state health regulators should prohibit licensed health professionals from accepting any such payments or incentives from the industry," Linda Richter, director of policy analysis and research for the Center on Addiction, told U.S. News and World Report. "Although physicians might believe that industry marketing efforts have no impact on their prescribing choices, a large body of evidence proves otherwise." Marianne Dodson

After three British tourists died from snorting what they thought was cocaine, head shops in Amsterdam (called "smart shops") will start selling kits to test drugs for heroin.

The inexpensive kits will be also be available for purchase through street teams, Amsterdam's Het Parool reports. The tourists, all in their early 20s, were found dead after ingesting what turned out to be "white heroin," Agence France Presse reports. At least 17 other visitors have required medical assistance after suffering from respiratory failure, police say.

Electronic signs have been put up around Amsterdam, warning people that "extremely dangerous cocaine is being sold to tourists," and Amsterdam's mayor, Eberhard van der Laan, is hopeful that the tests will help prevent more deaths. He doesn't see selling the kits as a show of support for doing drugs. "Not doing anything would be bad for the city," he said. "Amsterdam will do anything to prevent more victims. This is the least we can do." Catherine Garcia

In Southern California, one county is seeing more and more senior citizens dying from methamphetamine intoxication.

In 2012, San Diego County health records showed that "a majority of deaths attributed to methamphetamine were among Baby Boomers," NBC San Diego reports; the deaths included 69 people between the ages of 50 and 59 and 13 people older than 60. In 2013, 80 people age 45 to 54, 48 people between 55 and 64, and four people older than 65 had meth-related deaths.

"A lot of grandmas and grandpas are using meth and have been using for many, many years," Diana Julian, program manager for the McAlister Institute in El Cajon, California, told NBC San Diego.

The recent death of a San Diego man brought attention to this growing problem. Carl Salayer, 67, disappeared June 16, and a massive search-and-rescue effort was made to find him. More than a week later his body was discovered by San Diego County Sheriff's Deputies in a field. According to the autopsy, the official cause of death was acute methamphetamine intoxication.

Julian said more older people are taking meth for a variety of factors, including declining health. In some cases, the person doesn't have anyone there willing to help them stop. "For people that are using and they're older, their support has become smaller and smaller throughout the years," she said. Catherine Garcia